U.S. patent application number 14/902258 was filed with the patent office on 2017-04-13 for method and devices for mitigating error propagation in transmission assignments.
The applicant listed for this patent is TELEFONAKTIEBOLAGET LM ERICSSON (PUBL). Invention is credited to Erik Eriksson, Pal Frenger, Jonas Froberg Olsson, Martin Hessler.
Application Number | 20170105197 14/902258 |
Document ID | / |
Family ID | 58499213 |
Filed Date | 2017-04-13 |
United States Patent
Application |
20170105197 |
Kind Code |
A1 |
Froberg Olsson; Jonas ; et
al. |
April 13, 2017 |
Method and Devices for Mitigating Error Propagation in Transmission
Assignments
Abstract
A method in a wireless communication device for communication
with a radio network node comprises receiving (210) of a first
downlink control information on a first assignment. The first
downlink control information comprises a reference to a second
assignment, on which a second downlink control information is
assigned to be received. It is determined (220) if the second
downlink control information is obtainable. An indication
indicating whether or not the second downlink control information
was obtainable is transmitted (230) to the radio network node. A
method in the radio network node for communication with the
wireless communication device comprises transmitting of the first
and second downlink control information. It is determined whether
or not the second downlink control information was obtainable by
the wireless communication device and based in this, a third
downlink control information is transmitted on a third assignment.
Corresponding devices and computer programs are also described.
Inventors: |
Froberg Olsson; Jonas;
(Ljungsbro, SE) ; Eriksson; Erik; (Linkoping,
SE) ; Frenger; Pal; (Linkoping, SE) ; Hessler;
Martin; (Linkoping, SE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
TELEFONAKTIEBOLAGET LM ERICSSON (PUBL) |
Stockholm |
|
SE |
|
|
Family ID: |
58499213 |
Appl. No.: |
14/902258 |
Filed: |
November 11, 2015 |
PCT Filed: |
November 11, 2015 |
PCT NO: |
PCT/SE2015/051197 |
371 Date: |
December 30, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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62240953 |
Oct 13, 2015 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04L 1/1812 20130101;
H04W 72/042 20130101; H04L 27/2602 20130101; H04L 1/1896 20130101;
H04L 27/18 20130101; H04L 5/14 20130101; H04L 5/0053 20130101; H04W
72/0446 20130101 |
International
Class: |
H04W 72/04 20060101
H04W072/04; H04L 5/14 20060101 H04L005/14; H04L 1/18 20060101
H04L001/18; H04L 5/00 20060101 H04L005/00; H04L 27/18 20060101
H04L027/18 |
Claims
1-48. (canceled)
49. A method in a wireless communication device for communication
with a radio network node, said method comprising the steps of:
receiving a first downlink control information on a first
assignment from said radio network node; said first downlink
control information comprising a reference to a second assignment
from said radio network node on which a second downlink control
information is assigned to be received; determining if said second
downlink control information is obtainable by said wireless
communication device; and transmitting an indication indicating
whether or not said second downlink control information was
obtainable to said radio network node.
50. The method according to claim 49, wherein said first assignment
is an assignment in a physical control channel.
51. The method according to claim 49, wherein said first assignment
is an assignment in a physical data channel.
52. The method according to claim 49, wherein said second
assignment is an assignment in a physical data channel.
53. The method according to claim 52, wherein said steps of
determining if said second downlink control information is
obtainable by said wireless communication device and transmitting
the indication indicating whether or not said second downlink
control information was obtainable to said radio network node are
triggered by said second assignment being an assignment in a
physical data channel.
54. The method according to claim 49, wherein said steps of
determining if said second downlink control information is
obtainable by said wireless communication device and transmitting
the indication indicating whether or not said second downlink
control information was obtainable to said radio network node are
performed according to standard specifications for particular
transmission modes.
55. The method according to claim 49, wherein said steps of
determining if said second downlink control information is
obtainable by said wireless communication device and transmitting
the indication indicating whether or not said second downlink
control information was obtainable to said radio network node are
requested by a configuration message sent from said radio network
node to said wireless communication device.
56. The method according to claim 49, wherein said steps of
determining if said second downlink control information is
obtainable by said wireless communication device and transmitting
the indication indicating whether or not said second downlink
control information was obtainable to said radio network node are
requested by an indicator request in a downlink control
information.
57. The method according to claim 56, wherein said indicator
request comprises a resource assignment for said transmitting of
said indication.
58. The method according to claim 57, wherein said indicator, if
said resource assignment for said transmitting of said indication
is assigned to a same assignment for an already granted uplink
assignment, is incorporated in an uplink message on said same
assignment for an already granted uplink assignment and the
particular assignment for the transmitting of the indication is
ignored.
59. The method according to claim 49, wherein said first downlink
control information is comprised in a medium access control
element.
60. The method according to claim 49, wherein said second downlink
control information is comprised in a medium access control
element.
61. The method according to claim 49, wherein said indication is
transmitted on a contention-based resource.
62. The method according to claim 49, wherein said indication is
incorporated into an already granted uplink assignment.
63. The method according to claim 49, wherein said transmitting of
the indication is performed using binary phase shift keying
signaling.
64. The method according to claim 49, wherein said transmitting of
the indication is performed only if said second downlink control
information was obtainable.
65. The method according to claim 49, wherein said transmitting of
the indication is performed only if said second downlink control
information was not obtainable.
66. The method according to claim 49, wherein said transmitting of
the indication performed using ON/OFF signaling.
67. A method in a radio network node for communication with a
wireless communication device, said method comprising the steps of:
transmitting a first downlink control information on a first
assignment to said wireless communication device; said first
downlink control information comprises a reference to a second
assignment; transmitting a second downlink control information on
said second assignment to said wireless communication device;
determining whether or not said second downlink control information
was obtainable by said wireless communication device; and
transmitting a third downlink control information on a third
assignment based on said determining whether or not said second
downlink control information was obtainable by said wireless
communication device.
68. The method according to claim 67, wherein said third downlink
control information comprises an initiation of a resending of
messages associated with said second downlink control
information.
69. The method according to claim 67, wherein said step of
transmitting the third downlink control information comprises
transmitting, as a response to a determination that said second
downlink control information was not obtainable by said wireless
communication device, said third downlink control information.
70. The method according to claim 67, wherein said step of
determining whether or not said second downlink control information
was obtainable by said wireless communication device comprises
receiving of an indication from said wireless communication device
indicating that said second downlink control information was not
obtainable by said wireless communication device.
71. The method according to claim 70, wherein the indication is
received on a contention-based resource.
72. The method according to claim 70, wherein the indication is
incorporated into an uplink assignment.
73. The method according to claim 70, wherein said receiving of the
indication is performed using binary phase shift keying
signaling.
74. The method according to claim 70, wherein said receiving of the
indication is performed using ON/OFF signaling.
75. The method according to claim 67, wherein said step of
determining whether or not said second downlink control information
was obtainable by said wireless communication device comprises
determining an absence of an indication from said wireless
communication device indicating that said second downlink control
information was obtainable by said wireless communication device
when such an indication was expected to be received.
76. The method according to claim 67, wherein said first assignment
is an assignment in a physical control channel.
77. The method according to claim 67, wherein said first assignment
is an assignment in a physical data channel.
78. The method according to claim 67, wherein said second
assignment is an assignment in a physical data channel.
79. The method according to claim 67, further comprising the step
of transmitting, to said wireless communication device, a request
for transmitting an indication indicating whether or not said
second downlink control information was obtainable by said wireless
communication device.
80. The method according to claim 79, wherein said request for
transmitting the indication is comprised in a configuration
message.
81. The method according to claim 79, wherein said request for
transmitting the indication is comprised in a downlink control
information.
82. The method according to claim 81, wherein said indicator
request comprises a resource assignment for said transmitting of
the indication.
83. The method according to claim 67, wherein said first downlink
control information is comprised in a medium access control
element.
84. The method according to claim 67, wherein said second downlink
control information is comprised in a medium access control
element.
85. A wireless communication device configured to: receive a first
downlink control information on a first assignment from a radio
network node; said first downlink control information comprises a
reference to a second assignment from said radio network node on
which a second downlink control information is assigned to be
received; determine if said second downlink control information is
obtainable by said wireless communication device; and transmit an
indication indicating whether or not said second downlink control
information was obtainable to said radio network node.
86. The wireless communication device according to claim 85,
wherein said wireless communication device comprises a processor
and a memory, said memory comprising instructions executable by the
processor, whereby the processor is operative to determine if said
second downlink control information is obtainable by said wireless
communication device.
87. The wireless communication device according to claim 85,
wherein the wireless communication device comprises communication
circuitry configured to receive said first downlink control
information on said first assignment from said radio network node,
and to transmit said indication indicating whether or not said
second downlink control information was obtainable to said radio
network node.
88. A radio network node configured to: transmit a first downlink
control information on a first assignment to a wireless
communication device; said first downlink control information
comprises a reference to a second assignment; transmit a second
downlink control information on said second assignment to said
wireless communication device; determine whether or not said second
downlink control information was obtainable by said wireless
communication device; and transmit a third downlink control
information on a third assignment based on said determining whether
or not said second downlink control information was obtainable by
said wireless communication device.
89. The radio network node according to claim 88, wherein said
radio network node comprises a processor and a memory, said memory
comprising instructions executable by the processor, whereby the
processor is operative to determine whether or not said second
downlink control information was obtainable by said wireless
communication device.
90. The radio network node according to claim 88, wherein the radio
network node comprises communication circuitry configured to
transmit said first assignment, to transmit said first downlink
control information on said first assignment to said wireless
communication device, to transmit said second downlink control
information on said second assignment to said wireless
communication device, and to transmit said third downlink control
information on said third assignment to said wireless communication
device.
91. A non-transitory computer-readable medium storing a computer
program comprising instructions, that when executed by at least one
processor of a wireless communication device, configure the
wireless communication device to receive a first downlink control
information on a first assignment from a radio network node, said
first downlink control information comprising a reference to a
second assignment from said radio network node on which a second
downlink control information is assigned to be received, to
determine if said second downlink control information is obtainable
by a wireless communication device, and to transmit an indication
indicating whether or not said second downlink control information
was obtainable by a wireless communication device.
92. A non-transitory computer-readable medium storing a computer
program comprising instructions, that when executed by at least one
processor of a radio network node, configure the radio network node
to transmit a first downlink control information on a first
assignment to a wireless communication device, said first downlink
control information comprises a reference to a second assignment,
to transmit a second downlink control information on said second
assignment to said wireless communication device, to determine
whether or not said second downlink control information was
obtainable by said wireless communication device, and to transmit a
third downlink control information on a third assignment based on
said determining whether or not said second downlink control
information was obtainable by said wireless communication
device.
93. A wireless communication device, comprising: a receiver for
receiving a first downlink control information on a first
assignment from a radio network node, said first downlink control
information comprising a reference to a second assignment from said
radio network node on which a second downlink control information
is assigned to be received; a processing circuit configured to
determine whether said second downlink control information is
obtainable by said wireless communication device, and to transmit,
via a transmitter of the wireless communication device, an
indication indicating whether or not said second downlink control
information was obtainable by said wireless communication
device.
94. A radio network node, comprising: a transmitter for
transmitting a first downlink control information on a first
assignment to a wireless communication device, said first downlink
control information comprises a reference to a second assignment;
said transmitter being further for transmitting a second downlink
control information on said second assignment to said wireless
communication device; and a processing circuit configured to
determine whether or not said second downlink control information
was obtainable by said wireless communication device, and to
transmit, via said transmitter, a third downlink control
information on a third assignment based on said determining whether
or not said second downlink control information was obtainable by
said wireless communication device.
Description
TECHNICAL FIELD
[0001] The proposed technology generally relates to wireless
communication devices for communication with a radio network node,
methods in a wireless communication device for communication with a
radio network node, radio network nodes for communication with a
wireless communication device and methods in a radio network node
for communication with a wireless communication device. In
particular, the proposed technology relates to methods and devices
for mitigating error propagation in transmission assignments.
BACKGROUND
[0002] In wireless communication network, information about the
format in which the data is to be communicated between network
nodes is transmitted as control information in a specified and
known way. The receiving node, e.g. a User Equipment (UE) in a Long
Term Evolution (LTE) network, first decodes the control
information, also referred to as a grant, which control information
contains information on the transport format of the transmitted
downlink data and/or the data to be transmitted uplink. Examples of
the formatting information are allocation, i.e. where the data is
located, typically in frequency, number of layers used, modulation
and coding information, and HARQ process index.
[0003] In LTE networks, the grant is transmitted on a Physical
Downlink Control Channel (PDCCH) or an enhanced Physical Downlink
Control Channel (ePDCCH) using a variety of Downlink Control
Information (DCI) formats which are specific to different operating
modes of the UE. For example, in the random access procedure the
Enhanced NodeB (eNB), when sending a random access response to the
UE, uses a DCI format 1A. The eNB uses this format since this is
known to all UEs and the eNB does not know the actual capabilities
of the UE when sending the random access response. Later in the
call setup procedure the eNB learn the UE capabilities and can
start using a more advanced DCI format.
[0004] A grant received on PDCCH/ePDCCH is relative a specific
subframe (except semi-persistent grants that are relative multiple
subframes). For downlink (DL) the grant is typically specific to
same subframe n in which the grant was detected, while for uplink
(UL) the grant is typically specific to a future subframe n+a.
Usually a=4.
[0005] In some scenarios it would be desired to send the next grant
inside a granted PDCH transmission. Such a nested scenario of
grants will in the present disclosure be denoted as a "daisy
chain". However, the daisy chain scheme suffers from error
propagation.
[0006] If UE fails to detect the first grant on PCCH the UE will
also fails to detect sub-sequent transmissions on PDCH, and the UE
will not send anything in UL either. Error propagation can be
terminated due to that eNB detects that UE does not perform a
granted UL transmission. Although that error propagation can he
terminated after some time the performance loss can still be
significant. Hence, a better method for mitigating error
propagation is needed before a daisy-chain scheme can provide
acceptable performance.
SUMMARY
[0007] It is thus an object to provide improved mitigation of error
propagation in a process where a first downlink control information
comprises a reference to a second assignment, on which a second
downlink control information is assigned to be received.
[0008] This and other objects are met by embodiments of the
proposed technology.
[0009] According to a first aspect, there is provided a method in a
wireless communication device for communication with a radio
network node. The method comprises receiving of a first downlink
control information on a first assignment from the radio network
node. The first downlink control information comprises a reference
to a second assignment from the radio network node on which a
second downlink control information is assigned to be received. It
is determined if the second downlink control information is
obtainable by the wireless communication device. An indication
indicating whether or not the second downlink control information
was obtainable is transmitted to the radio network node.
[0010] According to a second aspect, there is provided a method in
a radio network node for communication with a wireless
communication device. The method comprises transmitting of a first
downlink control information on a first assignment to the wireless
communication device. The first downlink control information
comprises a reference to a second assignment. A second downlink
control information is transmitted on the second assignment to the
wireless communication device. It is determined whether or not the
second downlink control information was obtainable by the wireless
communication device. A third downlink control information is
transmitted on a third assignment based on the determining whether
or not the second downlink control information was obtainable by
the wireless communication device.
[0011] According to a third aspect, there is provided a wireless
communication device, configured to receive a first downlink
control information on a first assignment from a radio network
node. The first downlink control information comprises a reference
to a second assignment from the radio network node on which a
second downlink control information is assigned to be received. The
wireless communication device is further configured to determine if
the second downlink control information is obtainable by the
wireless communication device and to transmit, to the radio network
node, an indication indicating whether or not the second downlink
control information was obtainable.
[0012] According to a fourth aspect, there is provided a radio
network node, configured to transmit a first downlink control
information on a first assignment to a wireless communication
device. The first downlink control information comprises a
reference to a second assignment. The radio network node is further
configured to transmit a second downlink control information on the
second assignment to the wireless communication device, to
determine whether or not the second downlink control information
was obtainable by the wireless communication device, and to
transmit a third downlink control information on a third assignment
based on the determining whether or not the second downlink control
information was obtainable in the wireless communication
device.
[0013] According to a fifth aspect, there is provided a computer
program comprising instructions, which when executed by at least
one processor, cause the at least one processor to receive a first
downlink control information on a first assignment from a radio
network node, the first downlink control information comprises a
reference to a second assignment from the radio network node on
which a second downlink control information is assigned to be
received, to determine if the second downlink control information
is obtainable by the wireless communication device, and to transmit
an indication indicating whether or not the second downlink control
information was obtainable by the wireless communication
device.
[0014] According to a sixth aspect, there is provided a computer
program comprising instructions, which when executed by at least
one processor, cause the at least one processor to transmit a first
downlink control information on a first assignment to a wireless
communication device, the first downlink control information
comprises a reference to a second assignment, to transmit a second
downlink control information, on the second assignment to the
wireless communication device, to determine whether or not the
second downlink control information was obtainable by the wireless
communication device, and to transmit a third downlink control
information on a third assignment based on said determining whether
or not the second downlink control information was obtainable in
the wireless communication device.
[0015] According to a seventh aspect, there is provided a
computer-program product comprising a computer-readable medium
having stored thereon a computer program according to the fifth or
sixth aspect.
[0016] According to an eight aspect, there is provided a carrier
comprising the computer program of the fifth or sixth aspect,
wherein the carrier is one of an electronic signal, an optical
signal, an electromagnetic signal, a magnetic signal, an electric
signal, a radio signal, a microwave signal, or a computer-readable
storage medium.
[0017] According to a ninth aspect, there is provided a wireless
communication device, comprising a receiver for receiving a first
downlink control information on a first assignment from a radio
network node. The first downlink control information comprises a
reference to a second assignment from the radio network node on
which a second downlink control information is assigned to be
received. The wireless communication device further comprises a
determining module for determining if the second downlink control
information is obtainable by the wireless communication device, and
a transmitter for transmitting an indication indicating whether or
not the second downlink control information was obtainable by the
wireless communication device.
[0018] According to a tenth aspect, there is provided a radio
network node, comprising: a transmitter for transmitting a first
downlink control information on a first assignment to a wireless
communication device. The first downlink control information
comprises a reference to a second assignment. The transmitter is
further for transmitting a second downlink control information on
the second assignment to the wireless communication device. The
radio network node further comprises a determination module for
determining whether or not the second downlink control information
was obtainable by the wireless communication device. The
transmitter is further for transmitting a third downlink control
information on a third assignment based on the determining whether
or not the second downlink control information was obtainable in
the wireless communication device.
[0019] By detecting that a UE has missed one DCI message then the
base station can conclude that other DCI messages transmitted at
the same time, e.g. using the same physical channel and the same
Cyclic Redundancy Check (CRC), are also probably lost. An advantage
of the proposed technology is thus that any errors in a chain of
nested DCI are discovered early and a fast recovery is enabled.
[0020] Other advantages will be appreciated when reading the
further description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The embodiments, together with further objects and
advantages thereof, may best be understood by making reference to
the following description taken together with the accompanying
drawings, in which:
[0022] FIG. 1 is an illustration of data transmissions relating to
a specific UE;
[0023] FIG. 2 illustrates daisy-chain grants transmitted inside
granted PDCH transmission:
[0024] FIG. 3 illustrates error propagation in a daisy-chain;
[0025] FIG. 4 illustrates error propagation if a UE fails to decode
a second PDCH;
[0026] FIG. 5 illustrates possible error recovery in a
daisy-chain;
[0027] FIG. 6 is a schematic flow diagram illustrating an
embodiment of a method in a wireless communication device for
communication with a radio network node;
[0028] FIG. 7 is a schematic flow diagram illustrating an
embodiment of a method in a radio network node for communication
with a wireless communication device;
[0029] FIG. 8 is a schematic illustration of a wireless
communication system 1;
[0030] FIG. 9 illustrates an embodiment of a daisy-chain status
grant approach for early recovery;
[0031] FIG. 10 illustrates that a previously granted resource can
be used to indicate daisy chain status feedback;
[0032] FIG. 11 is a schematic block diagram illustrating an
embodiment of a wireless communication device;
[0033] FIG. 12 is a schematic block diagram illustrating an
embodiment of a radio network node;
[0034] FIG. 13 is a schematic diagram illustrating an example of a
computer-implementation according to an embodiment of a wireless
communication device;
[0035] FIG. 14 is a schematic diagram illustrating an example of a
computer-implementation according to an embodiment of a radio
network device;
[0036] FIG. 15 is a schematic diagram illustrating an example of a
wireless communication device; and
[0037] FIG. 16 is a schematic diagram illustrating an example of a
radio network node.
DETAILED DESCRIPTION
[0038] Throughout the drawings, the same reference designations are
used for similar or corresponding elements.
[0039] For a better understanding of the proposed technology, it
may be useful to begin with a brief overview of the present use of
daisy chains and/or analysis of the technical problem.
[0040] FIG. 1 is an illustration of data transmissions relating to
a specific UE in a Frequency Division Duplex (FDD) system. The
arrows illustrate which DL respective UL transmission respective
grant transmitted on the Physical Control Channel (PCCH) relate to.
Here a=4 is illustrated, i.e. an uplink grant provided on the PCCH
in sub-frame n is valid for uplink transmission in sub-frame
n+4.
[0041] FIG. 1 thus illustrates a FDD system with a downlink PCCH
and two Physical Data Channels (PDCHs), one for DL and one for UL.
One DL and one UL grant is transmitted in each subframe during the
session in which the UE has data. The scenario illustrated is a DL
data session wherein the UE has downlink data to be transmitted for
8 subframes. The UL grants are present for the UE to provide Hybrid
Automatic Repeat-reQuest (HARQ) feedback, and possibly also
Channel-State Information (CSI) feedback and higher layer feedback,
to the eNB.
[0042] As mentioned above, in some scenarios it would be desired to
send the next grant inside a granted PDCH transmission. A UE will
thereby receive a first DCI on a first assignment from the radio
network node. That first DCI comprises a reference to a second
assignment from the radio network node on which a second DCI is
assigned to be received, i.e. a "daisy chain". Such an approach
would offload PCCH due to that only the first PCCH transmission
would occur during the session.
[0043] FIG. 2 illustrates daisy-chain grants transmitted inside
granted PDCH transmission. Only one first grant on PCCH would be
required to start the daisy chain. As a result, dimensioning of
PCCH could be reduced and more resources could be allocated to PDCH
resulting in increased throughput.
[0044] FIG. 3 illustrates error propagation. If UE fails to detect
the first grant on PCCH the UE will also fail to detect sub-sequent
transmissions on PDCH, and the UE will not send anything in UL
either.
[0045] FIG. 4 illustrates error propagation if the UE fails to
decode a second PDCH. As a result the UE stops receiving DL data
for sub-frames n.gtoreq.n.sub.0+2, where n.sub.0 being the
sub-frame where the initial PCCH transmission took place.
Furthermore, the UE will not have a grant for uplink transmission
in sub-frame n.sub.0+5.
[0046] FIG. 5 illustrates a possible error recovery. eNB knows it
scheduled the UE in UL subframe n.sub.0+4 and can hence detect a
missing UL transmission from the UE and can therefore recover from
error propagation in this particular scenario. FIG. 5 thus
illustrates a scenario wherein error propagation can be terminated
due to that eNB detects that UE does not perform a granted UL
transmission. The method of detecting missing UL grants has been
used to enable link adaptation on the control channel (e.g.
PDCCH/ePDCCH in LTE). Although that error propagation can be
terminated after some time, as mentioned above, the performance
loss can still he significant.
[0047] The performance loss can be reduced by shortening the time
it takes for the radio network node to realize that there is an
error in the nested scenario of grants. A set of nested grants are
transmitted by a radio network node to a wireless communication
device. The wireless communication device is instructed, implicitly
or explicitly, to determine if the downlink control information in
the nested grants is obtainable by the wireless communication
device. This can be performed very quickly. An indication
indicating whether or not the second downlink control information
was obtainable may therefore be transmitted back to the radio
network node very soon after the reception of the nested grants,
typically in a following transmission time interval, but in certain
cases even in a present transmission time interval. The radio
network node can then by monitoring the reception of indications or
the absence of expected indications perform an early detection of
an error. The radio network node may therefore initiate a process
for compensating the errors faster than what has been possible in
prior art systems.
[0048] The alternatives how to perform the communication, on which
resources and under what circumstances, are many. Some of them will
be described more in detail in the different descriptions of
embodiments here below.
[0049] FIG. 6 is a schematic flow diagram illustrating an
embodiment of a method in a wireless communication device for
communication with a radio network node. The process starts in step
200. The method comprises in step 210 receiving of a first downlink
control information on a first assignment from the radio network
node. The first downlink control information comprises a reference
to a second assignment from the radio network node. On this second
assignment, a second downlink control information is assigned to be
received.
[0050] This may correspond to a part of a daisy chain. In one
alternative, the first DCI on the first assignment can be the
original DCI sent on a control channel. In other words, the first
assignment is an assignment in a physical control channel. The
second DCI on the second assignment can be the first DCI in the
daisy chain transmitted on the data channel. In another
alternative, the first DCI on the first assignment can be a DCI
sent on a control channel, e.g. in the middle of a daisy chain. In
other words, the first assignment is an assignment in a physical
data channel. The second DCI on the second assignment is then the
next DCI in the daisy chain transmitted on the data channel. In
both these alternatives, the second assignment is an assignment in
a physical data channel.
[0051] The embodiment of FIG. 6 then further comprises step 220 of
determining if the second downlink control information is
obtainable by the wireless communication device. Finally, in step
230 an indication indicating whether or not the second downlink
control information was obtainable is transmitting to the radio
network node. The process is ended in step 249.
[0052] One particular embodiment of a method in a wireless
communication device that is capable of receiving assignments from
a radio network node on a physical control channel and one or more
scheduled physical data channels comprises obtaining of a grant for
transmission of an "inband-control reception" indicator. The grant
may utilize a contention based channel, an explicit control
channel, a specific reference signal, or an inband-control message,
or a channel explicitly encoded in the standard. The method further
comprises transmitting of an "inband-control reception" indicator
using the grant indicating success and/or failure of inband-control
reception. The inband-control messages can be transmitted on the
one or more physical data channels. The encoding of the message may
be on/off keying or Binary Phase Shift Keying (BPSK).
[0053] Here many different alternatives are possible. One
particular example could be that a UL resource, as a part of the
second DCI, is granted for transmitting an indication. If a UE is
not transmitting on such a granted UL resource, this indicates to
the base station that DCIs corresponding to the DCI transmissions
were lost as well as any additional DCI messages that were embedded
in the lost transmissions.
[0054] A UE that was given a dynamically scheduled UL resource may
use a contention based resource for transmitting the indication.
Such transmissions could be limited to occasions when faults are
detected, e.g. when granted DCIs are not obtainable by the UE,
and/or at the start and end of a daisy chain.
[0055] In another embodiment, a UE that has a UL grant for frame
n+1, provided earlier, was expecting to receive a DL transmission
in frame n but no such transmission was received. In that case the
UE may send a special message to the base station, using the grant
it has, indicating that any DCIs transmitted in sub-frame n were
lost. The special message may in a particular embodiment comprise
an extension of the message intended for the granted resource
comprising the indication.
[0056] As mentioned further above, in situations like these the
base station need to recover from the error event chain by sending
a new DCI on a channel that is outside of the control information
daisy chain, e.g. on the PCCH.
[0057] FIG. 7 is a schematic flow diagram illustrating an
embodiment of a method in a radio network node for communication
with a wireless communication device. The process starts in step
250. The method comprises step 260 of transmitting of a first
downlink control information on a first assignment to the wireless
communication device. The first downlink control information
comprises a reference to a second assignment. The method further
comprises step 262 of transmitting of a second downlink control
information on the second assignment to the wireless communication
device.
[0058] This may correspond to a part of a daisy chain. In one
alternative, the first DCI on the first assignment can be the
original DCI sent on a control channel. In other words, the first
assignment is an assignment in a physical control channel. The
second DCI on the second assignment can be the first DCI in the
daisy chain transmitted on the data channel. In another
alternative, the first DCI on the first assignment can be a DCI
sent on a control channel, e.g. in the middle of a daisy chain. In
other words, the first assignment is an assignment in a physical
data channel. The second DCI on the second assignment is then the
next DCI in the daisy chain transmitted on the data channel. In
both these alternatives, the second assignment is an assignment in
a physical data channel.
[0059] The embodiment of FIG. 7 then further comprises step 270 of
determining whether or not the second downlink control information
was obtainable by the wireless communication device. In step 280, a
third downlink control information is transmitted on a third
assignment based on the determining whether or not the second
downlink control information was obtainable in the wireless
communication device. The process ends in step 299.
[0060] In one embodiment, a method in a base station comprises, in
addition to the normal transmissions of a daisy chain, receiving of
an "inband-DCI reception" indicator from a UE. The method further
comprises transmitting of a new control messages on a control
channel or a data channel in dependence of the indicator. This new
control message could e.g. be transmitted in response to a negative
"inband-control reception" indicator from the UE. The next DCI
transmission is preferably performed on the physical control
channel. In response to a positive "inband-control reception"
indicator from the UE, the next DCI transmission can instead be
performed at a physical data channel, in accordance with the
original daisy chain.
[0061] In some particular embodiments the base station provides a
grant for the indicator explicitly to the mobile station.
[0062] In one embodiment, the UE transmits second indicator until
UE receives an assignment on physical control channel.
[0063] In some embodiments, the base station determines which
control messages should have been received during a normal session
but that were not received. The new control messages on the control
channel may then be derived in dependence on the not received
control messages.
[0064] In one embodiment, the transmitting of a third downlink
control information comprises transmitting the third downlink
control information as a response to a determination that the
second downlink control information was not obtainable by the
wireless communication device.
[0065] In a further embodiment, the third downlink control
information then comprises an initiation of a resending of messages
associated with the second downlink control information.
[0066] In another embodiment, the transmitting of a third downlink
control information comprises transmitting a next DCI in the daisy
chain as the third downlink control information, as a response to a
determination that the second downlink control information was
obtainable by the wireless communication device.
[0067] In one embodiment, the radio network node detects a daisy
chain error event when the UE is using a contention based channel
even though it is assigned a dedicated uplink grant.
[0068] In one embodiment, the fact that error events related to
DCIs that are transmitted using a common CRC are correlated are
utilized. One example is if a DL grant for sub-frame n is reported
as missing, then UL grant for sub-frame n+a is also lost,
especially in case they were jointly encoded.
[0069] FIG. 8 is a schematic illustration of a wireless
communication system 1. A radio network node 10 is, by transmitting
and receiving radio signals via an antenna 12, in radio contact
with a wireless communication device 20. The radio network node 10
is in further contact, as illustrated by the line 14, with other
nodes of the wireless communication system 1. The radio network
node 10 may be in contact with several wireless communication
devices, as indicated by the broken line figures. The radio network
node 10 can thus send e.g. downlink control information to a group
of wireless communication devices 20.
[0070] The radio network node 10 may in particular embodiments
control the transmission from more than one antenna, as indicated
by the broken line figures. The radio network node 10 should be
considered as a logical node controlling potentially many physical
nodes. For example, the radio network node 10 can control several
transmission points, e.g., antenna sites, and a control message
could be sent from any of the transmission points.
[0071] As used herein, the non-limiting terms "User Equipment
(UE)", "station (STA)" and "wireless communication device" may
refer to a mobile phone, a cellular phone, a Personal Digital
Assistant (PDA) equipped with radio communication capabilities, a
smart phone, a laptop or Personal Computer (PC) equipped with an
internal or external mobile broadband modem, a tablet PC with radio
communication capabilities, a target device, a device to device UE,
a machine type UE or UE capable of machine to machine
communication, iPAD, Customer Premises Equipment (CPE), Laptop
Embedded Equipment (LEE), Laptop Mounted Equipment (LME), Universal
Serial Bus (USB) dongle, a portable electronic radio communication
device, a sensor device equipped with radio communication
capabilities or the like. In particular, the term "UE", the term
"Station" and the term "wireless communication device" should be
interpreted as non-limiting terms comprising any type of wireless
device communicating with a network node in a wireless
communication system and/or possibly communicating directly with
another wireless communication device. In other words, a wireless
communication device may be any device equipped with circuitry for
wireless communication according to any relevant standard for
communication.
[0072] As used herein, the non-limiting term "radio network node"
may refer to base stations, access points, network control nodes
such as network controllers, radio network controllers, base
station controllers, access controllers, and the like. In
particular, the term "base station" may encompass different types
of radio base stations including standardized base stations such as
Node Bs, or evolved Node Bs (eNB) and also macro/micro/pico radio
base stations, home base stations, also known as femto base
stations, relay nodes, repeaters, radio access points, Base
Transceiver Stations (BTS), and even radio control nodes
controlling one or more Remote Radio Units (RRU), or the like.
[0073] In the following, the general non-limiting term
"communication unit" includes network nodes and/or associated
wireless devices.
[0074] It will be appreciated that the methods and devices
described herein can be combined and re-arranged in a variety of
ways.
[0075] In FIG. 9, the events and signaling of an embodiment of a
daisy chain status grant approach for early recovery are
illustrated. Early recovery can in short be achieved due to that
the eNB knows it has scheduled the UE for daisy chain status grant
for UL subframe n.sub.0+2 and can hence detect a missing UL
transmission from the UE. The eNB can therefore recover from error
propagation in this particular scenario. Subframe n.sub.0+4
illustrate that `normal` UL grants are given priority over daisy
chain status grants.
[0076] In a preferred version of this embodiment, the physical data
channel is as illustrated consisting of two parts, a direct and a
re-transmittable field, that are separately encoded. These two
parts can be viewed as two physical data channels. A direct
channel, direct Physical Data Channel (dPDCH), is transmitted
preferably in a first part of OFDM symbols within the TTI while a
re-transmittable channel, re-transmittable Physical Data Channel
(rPDCH), is transmitted in the remaining Orthogonal
Frequency-Division Multiplexing (OFDM) symbols. The first channel
dPDCH carries typically data for which decoding-related information
need not be retained by a receiving node in the event of an
unsuccessful decoding of data. The second channel rPDCH carries
retransmittable data, i.e. data that will be retransmitted in the
event that a negative acknowledgement is received by a transmitting
node, or in some cases in the event that an acknowledgement is not
received. For the rPDCH, the decoding-related information can be
retained by the receiving node in the event of an unsuccessful
decoding of data, for use in combining with decoding-related
information obtained when decoding the corresponding retransmitted
data. The dPDCH and rPDCH can each in principle carry both control
and user data. In the present application, a preferred
implementation is to let the dPDCH comprise the DCI potentially
additionally to data, while the rPDCH is intended for user
data.
[0077] This preferred version is a case wherein the indication
possibly could be sent during same transmission time interval as
the grant, i.e. the assignment, was received
[0078] FIG. 9 illustrate such scenario wherein the dPDCH
corresponds to the first part of each Transmission Time Interval
(TTI) of the DL PDCH while rPDCH corresponds to the second part of
each TTI of the UL PDCH.
[0079] In other embodiments, the DCI may be comprised in rPDCH.
[0080] Returning to FIG. 9, when the eNB wants to initialize a
daisy chain scheme it sends a grant on PCCH that grants the dPDCH.
On the dPDCH the eNB includes a grant for next dPDCH. In this
particular embodiment, the dPDCH further comprises a grant for
rPDCH, and an UL grant that enables the UE to transmit the HARQ
feedback for the (current) granted rPDCH transmission.
[0081] The scheme has some similarities to the scheme illustrated
in FIG. 2, but FIG. 2 does not show the dPDCH and rPDCH channels.
In addition, the eNB also include an additional UL grant that
grants a UL transmission occurring earlier than the granted UL
transmission for sending HARQ feedback. This additional UL grant
can be viewed as a daisy chain status grant that enable early
detection of error propagation. In other words, in the radio
network node, the procedure comprises the step of transmitting, to
the wireless communication device, a request for transmitting an
indication indicating whether or not the second downlink control
information was obtainable by the wireless communication
device.
[0082] As illustrated in the FIG. 9, this embodiment of the method
enables early recovery of an error. The eNB sends a grant on PCCH
in subfrarne n.sub.0 and the dPDCH suhframe n.sub.0 contains four
grants: rPDCH grant, HARQ feedback grant, the next dPDCH grant and
the daisy chain status grant. Since the data granted by the daisy
chain status grant preferably is small the UE should be able to
perform an UL transmission far before it could be prepared to send
HARQ feedback or large payload data, probably being capable of
performing such a transmission already in the next subframe
n.sub.0+1, as illustrated in the figure.
[0083] In an alternative embodiment, the transmission may be
performed already in the same subframe n.sub.0.
[0084] In the embodiment of FIG. 9, the steps of determining if the
second downlink control information is obtainable by the wireless
communication device and transmitting an indication to said radio
network node, which indication indicates whether or not the second
downlink control information was obtainable, are requested by an
indicator request in a downlink control information. In particular,
the indicator request comprises in this embodiment a resource
assignment for the transmitting of the indication.
[0085] 9 also illustrate that the UE fails to decode the dPDCH in
suhframe n.sub.0+1 and therefore does not receive the daisy chain
status grant for suhframe n.sub.0+2. The missing UL transmission in
subframe n.sub.0+2 enable the eNB to detect that the daisy chain is
broken and can hence re-initialize the daisy chain again in
subframe n.sub.0+3. After that, the UE correctly decode dPDCH and
receives the grants.
[0086] In the embodiment of FIG. 9, the step of determining whether
or not the second downlink control information was obtainable by
the wireless communication device comprises determining an absence
of an indication from the wireless communication device indicating
that the second downlink control information was obtainable by the
wireless communication device when such an indication was expected
to be received.
[0087] In an alternative embodiment, the steps of determining if
the second downlink control information is obtainable by the
wireless communication device and transmitting an indication to
said radio network node, which indication indicates whether or not
said second downlink control information was obtainable, are
requested by a configuration message sent from the radio network
node to the wireless communication device.
[0088] In FIG. 9, in subframe n.sub.0+4 the UE does not perform the
UL transmission according to the daisy chain status grant since it
already has an UL grant, received already in subframe no. Hence,
the UE is in this embodiment configured so that `normal` UL grants
have priority over daisy chain status grants.
[0089] In another embodiment, if a grant of a `normal` UL
transmission, e.g. a HARQ feedback, and a grant of a daisy chain
status are scheduled to a same, the HARQ feedback may be modified
to comprise also information concerning the daisy chain status. In
other words, the indicator, if the resource assignment for the
transmitting of the indication is assigned to a same assignment for
an already granted uplink assignment, is incorporated in an uplink
message on the same assignment for an already granted uplink
assignment and the particular assignment for the transmitting of
the indication is ignored.
[0090] Although the use of dPDCH and rPDCH is a preferred
implementation, the basic technology of the present disclosure will
also operate without this specific implementation. The DCI may then
constitute the first portion of a data amount of the PDCH, which
portion is interpreted by the wireless communication device as
control data, comprising a grant of a further PDCH.
[0091] The daisy chain status grant may in some particular
embodiments be implicit in the sense that no explicit grant is
included in the dPDCH. Instead, it is the UE that detects a daisy
chain grant, i.e. a grant for next subframe, in e.g. a dPDCH
granted using PCCH. Hence, in such embodiments, the UE is
configured to indicate to eNB that the daisy chain has been
initialized, or in other words that the UE detected the daisy chain
grant. In some such embodiments, the UE could send an indication by
sending reference signals or a message, e.g. on a contention based
channel. In other words, the steps of determining if the second
downlink control information is obtainable by the wireless
communication device and transmitting an indication to the radio
network node, which indication indicates whether or not the second
downlink control information was obtainable, are triggered by the
second assignment simply being an assignment in a physical data
channel.
[0092] The implicit daisy chain status grant can also be concluded
by following a standard concerning different transmission modes.
The steps of determining if the second downlink control information
is obtainable by the wireless communication device and transmitting
an indication to said radio network node, which indication
indicates whether or not the second downlink control information
was obtainable, are performed according to standard specifications
for particular transmission modes. In other words, if certain
transmission modes are used, standards may define that a daisy
chain status is expected to be sent.
[0093] In one embodiment, the grants of a next DCI and/or a DL user
data message may not comprise explicit assignments of particular
channel elements on particular TTIs on particular channels.
Instead, the grants may comprise information about adapted
terminal-specific search spaces for the UE. A UE has typically a
standard terminal-specific search space which is searched for
possible messages to the UE. Upon starting a daisy chain, the grant
of a future DCI may comprise an adaptation of that
terminal-specific search space. The UE can then use this adapted
terminal-specific search space to look e.g. for a subsequent
control message. Such an adaptation of a terminal-specific search
space may e.g. comprise the instructions to search for a subsequent
control message on a number of channel elements in a downlink data
channel.
[0094] FIG. 10 illustrates an embodiment of a daisy chain status
feedback approach, where a previously granted resource, in
sub-frame n.sub.0+1, can be used to indicate daisy chain status
feedback.
[0095] In the embodiment of FIG. 10, the UE is configured to send
daisy chain indicator to eNB indicating the status of the daisy
chain. The daisy chain indicator enables the eNB to early detect a
broken daisy chain if for example the chain breaks in the middle
when the UE already has grants for UL transmissions as illustrated
in FIG. 10. The chain breaks in the subframe due to that decoding
of dPDCH fails. The UE that has received a UL grant for subframe
n.sub.0+1 from a previous decoded transmission include a daisy
chain status indicator in the transmission in n.sub.0+1 in the
figure.
[0096] In one embodiment, the grants of a next DCI and/or a DL user
data message may not comprise explicit assignments of particular
TTIs on particular channels. Instead, the grants may comprise
information about adapted search spaces for the UE. A UE has
typically a standard search space which is searched for possible
messages to the UE. Upon starting a daisy chain, the grant of a
future DCI may comprise an adaptation of the search space. The UE
can then use this adapted search space to look e.g. for a
subsequent control message.
[0097] In some other embodiments, a daisy chain broken indicator is
transmitted on separate UL channel, e.g. a contention-based
channel.
[0098] In other embodiments, the UE is not capable of sending daisy
chain status indicator already in subframe n.sub.0+1, but it send
the indicator in subframe n.sub.0+2 or n.sub.0+3.
[0099] The daisy chain status indicator can be combined with the
daisy chain status grant presented above wherein the status is
indicated in the data transmitted due to the daisy chain status.
The status indicator can in some embodiments be sent for every
detected daisy chain grant, i.e. a grant received on PDCH, and in
other examples be triggered by a failed decoding of a daisy chain
granted PDCH. In some such other examples, transmission of the
status indicator could be triggered when the daisy chain is
initialized, i.e. when a grant for upcoming TTI is granted and the
grant was detected on a PDCH granted on a PCCH, and if/when the
daisy chain is broken, i.e. UE fails to decode daisy chain granted
PDCH. In further such embodiments, the eNB may send a daisy chain
grant to the UE but decided not to make the PDCH transmission. In
such further examples, the UE sends the status indicator but keep
trying to decode PDCH using its received daisy chain grant for
future TTIs.
[0100] Thus, in particular embodiments, the transmitting of the
indication is performed only if the second downlink control
information was obtainable. In other particular embodiments, the
transmitting of the indication is performed only if the second
downlink control information was not obtainable. In such cases,
where only one alternative is possible in the indication,
transmitting of the indication may preferably be performed using
ON/OFF signalling.
[0101] In embodiments, where the transmitting of the indication can
be performed under different circumstances, the transmitting of the
indication may preferably be performed using binary phase shift
keying signalling.
[0102] The DCI can be comprised in the messages in different ways.
In a particular embodiment, the first downlink control information
is comprised in a medium access control element. Also in a
particular embodiment, the second downlink control information is
comprised in a medium access control element.
[0103] In one embodiment, in the radio network node, the step of
determining whether or not the second downlink control information
was obtainable by the wireless communication device comprises
receiving of an indication from the wireless communication device
indicating that the second downlink control information was not
obtainable by the wireless communication device.
[0104] Embodiments of the devices may be implemented in hardware,
or in software for execution by suitable processing circuitry, or a
combination thereof.
[0105] The steps, functions, procedures, modules and/or blocks
described herein may be implemented in hardware using any
conventional technology, such as discrete circuit or integrated
circuit technology, including both general-purpose electronic
circuitry and application-specific circuitry.
[0106] Alternatively, or as a complement, at least some of the
steps, functions, procedures, modules and/or blocks described
herein may be implemented in software such as a computer program
for execution by suitable processing circuitry such as one or more
processors or processing units.
[0107] Examples of processing circuitry includes, but is not
limited to, one or more microprocessors, one or more Digital Signal
Processors (DSPs), one or more Central Processing Units (CPUs),
video acceleration hardware, and/or any suitable programmable logic
circuitry such as one or more Field Programmable Gate Arrays
(FPGAs), or one or more Programmable Logic Controllers (PLCs).
[0108] It should also he understood that it may be possible to
re-use the general processing capabilities of any conventional
device or unit in which the proposed technology is implemented. It
may also be possible to re-use existing software, e.g. by
reprogramming of the existing software or by adding new software
components.
[0109] According to an aspect of the proposed technology there is
provided a wireless communication device, configured to receive a
first downlink control information on a first assignment from a
radio network node. The first downlink control information
comprises a reference to a second assignment from the radio network
node on which a second downlink control information is assigned to
be received. The wireless communication device is further
configured to determine if the second downlink control information
is obtainable by the wireless communication device, and to transmit
an indication indicating whether or not the second downlink control
information was obtainable to the radio network node.
[0110] According to an aspect of the proposed technology there is
provided a radio network node, being configured to transmit a first
downlink control information on a first assignment to a wireless
communication device. The first downlink control information
comprises a reference to a second assignment. The radio network
node is further configured to transmit a second downlink control
information on the second assignment to the wireless communication
device, to determine whether or not the second downlink control
information was obtainable by the wireless communication device,
and to transmit a third downlink control information on a third
assignment based on the determining whether or not he second
downlink control information was obtainable in the wireless
communication device.
[0111] FIG. 11 is a schematic block diagram illustrating an
embodiment of a wireless communication device 20, based on a
processor-memory implementation according to an embodiment. In this
particular example, the wireless communication device 20 comprises
a processor 121 and a memory 122, the memory 122 comprising
instructions executable by the processor 121, whereby the processor
is operative to determine if the second downlink control
information is obtainable by the wireless communication device.
[0112] The wireless communication device 20 also includes a
communication circuit 120. The communication circuit 120 includes
functions for wireless communication with other devices and/or
network nodes in the network. In a particular example, the
communication circuit 120 may be based on radio circuitry for
communication with one or more other nodes, including transmitting
and/or receiving information. The communication circuit 130 may be
interconnected to the processor 121 and/or memory 122. By way of
example, the communication circuit 120 may include any of the
following: a receiver, a transmitter, a transceiver, input/output
(I/O) circuitry, input port(s) and/or output port(s). The
communication circuit 120 is configured to receive the first
downlink control information on the first assignment from the radio
network node, and to transmit the indication indicating whether or
not the second downlink control information was obtainable to the
radio network node.
[0113] FIG. 12 is a schematic block diagram illustrating an
embodiment of a radio network node 10, based on a processor-memory
implementation according to an embodiment. In this particular
example, the radio network node 10 comprises a processor 111 and a
memory 112, the memory 112 comprising instructions executable by
the processor 111, whereby the processor is operative determine
whether or not the second downlink control information was
obtainable by the wireless communication device.
[0114] The radio network node 10 also includes a communication
circuit 110. The communication circuit 110 includes functions for
wireless communication with other devices and/or network nodes in
the network. In a particular example, the communication circuit 110
may he based on radio circuitry for communication with one or more
other nodes, including transmitting and/or receiving information.
The communication circuit 110 may be interconnected to the
processor 111 and/or memory 112. By way of example, the
communication circuit 110 may include any of the following: a
receiver, a transmitter, a transceiver, input/output (I/O)
circuitry, input port(s) and/or output port(s). The communication
circuit 110 is configured to transmit the first assignment, to
transmit the first downlink control information on the first
assignment to the wireless communication device, to transmit the
second downlink control information on the second assignment to the
wireless communication device, and to transmit the third downlink
control information on the third assignment to the wireless
communication device.
[0115] A hardware (HW) circuitry implementation of a wireless
communication device and/or a radio network node may include one or
more suitably configured or possibly reconfigurable electronic
circuitry, e.g. Application Specific Integrated Circuits (ASICs),
Field Programmable Gate Arrays (FPGAs), or any other hardware logic
such as circuits based on discrete logic gates and/or flip-flops
interconnected to perform specialized functions in connection with
suitable registers (REG), and/or memory units (MEM).
[0116] Another implementation a wireless communication device
and/or a radio network node may he based on combination of both
processor(s) and hardware circuitry in connection with suitable
memory unit(s). The arrangements comprises one or more processors,
memory including storage for software and data, and one or more
units of hardware circuitry such as ASICs and/or FPGAs. The overall
functionality is thus partitioned between programmed software (SW)
for execution on one or more processors, and one or more
pre-configured or possibly reconfigurable hardware circuits such as
ASICs and/or FPGAs. The actual hardware-software partitioning can
be decided by a system designer based on a number of factors
including processing speed, cost of implementation and other
requirements.
[0117] Alternatively, or as a complement, at least some of the
steps, functions, procedures, modules and/or blocks described
herein may be implemented in software such as a computer program
for execution by suitable processing circuitry such as one or more
processors or processing units.
[0118] The flow diagram or diagrams presented herein may therefore
be regarded as a computer flow diagram or diagrams, when performed
by one or more processors. A corresponding apparatus may be defined
as a group of function modules, where each step performed by the
processor corresponds to a function module. In this case, the
function modules are implemented as a computer program running on
the processor.
[0119] Examples of processing circuitry includes, but is not
limited to, one or more microprocessors, one or more Digital Signal
Processors (DSPs), one or more Central Processing Units (CPUs),
video acceleration hardware, and/or any suitable programmable logic
circuitry such as one or more Field Programmable Gate Arrays
(FPGAs), or one or more Programmable Logic Controllers (PLCs).
[0120] It should also be understood that it may be possible to
re-use the general processing capabilities of any conventional
device or unit in which the proposed technology is implemented. It
may also be possible to re-use existing software, e.g. by
reprogramming of the existing software or by adding new software
components.
[0121] FIG. 13 is a schematic diagram illustrating an example of a
computer-implementation according to an embodiment of a wireless
communication device 20. In this particular example, at least some
of the steps, functions, procedures, modules and/or blocks
described herein are implemented in a computer program 125, which
is loaded into the memory 122 for execution by processing circuitry
including one or more processors 121. The processor(s) 121 and
memory 122 are interconnected to each other to enable normal
software execution. An input/output device 123 may also be
interconnected to the processor(s) 121 and/or the memory 122 to
enable input and/or output of relevant data such as input messages
and/or resulting output messages or indications.
[0122] The term `processor` should be interpreted in a general
sense as any system or device capable of executing program code or
computer program instructions to perform a particular processing,
determining or computing task.
[0123] The processing circuitry including one or more processors
121 is thus configured to perform, when executing the computer
program 125, well-defined processing tasks such as those described
herein.
[0124] The processing circuitry does not have to be dedicated to
only execute the above-described steps, functions, procedure and/or
blocks, but may also execute other tasks.
[0125] In a particular embodiment, a computer-program product 127
comprises a computer-readable medium 126 comprising instructions,
which when executed by at least one processor 121, cause the
processor(s) 121 to perform the tasks described above.
[0126] FIG. 14 is a schematic diagram illustrating an example of a
computer-implementation according to an embodiment of a radio
network device 10. In this particular example, at least some of the
steps, functions, procedures, modules and/or blocks described
herein are implemented in a computer program 115, which is loaded
into the memory 112 for execution by processing circuitry including
one or more processors 111. The processor(s) 111 and memory 112 are
interconnected to each other to enable normal software execution.
An input/output device 113 may also be interconnected to the
processor(s) 111 and/or the memory 112 to enable input and/or
output of relevant data such as input messages or indications
and/or resulting output messages.
[0127] The term `processor` should be interpreted in a general
sense as any system or device capable of executing program code or
computer program instructions to perform a particular processing,
determining or computing task.
[0128] The processing circuitry including one or more processors
111 is thus configured to perform, when executing the computer
program 115, well-defined processing tasks such as those described
herein.
[0129] The processing circuitry does not have to be dedicated to
only execute the above-described steps, functions, procedure and/or
blocks, but may also execute other tasks.
[0130] In a particular embodiment, a computer-program product 117
comprises a computer-readable medium 116 comprising instructions,
which when executed by at least one processor 111, cause the
processor(s) 111 to perform the tasks described above.
[0131] In a particular embodiment, the computer program comprises
instructions, which when executed by at least one processor, cause
the at least one processor to receive a first downlink control
information on a first assignment from the radio network node, the
first downlink control information comprises a reference to a
second assignment from the radio network node on which a second
downlink control information is assigned to be received, to
determine if the second downlink control information is obtainable
by the wireless communication device, and to transmit an indication
indicating whether or not the second downlink control information
was obtainable to the radio network node.
[0132] In a particular embodiment, the computer program comprises
instructions, which when executed by at least one processor, cause
the at least one processor to transmit a first downlink control
information on a first assignment to the wireless communication
device, the first downlink control information comprises a
reference to a second assignment, to transmit a second downlink
control information on the second assignment to the wireless
communication device, to determine whether or not the second
downlink control information was obtainable by the wireless
communication device, and to transmit a third downlink control
information on a third assignment based on the determining whether
or not the second downlink control information was obtainable in
the wireless communication device.
[0133] The proposed technology also provides a carrier comprising
the computer program, wherein the carrier is one of an electronic
signal, an optical signal, an electromagnetic signal, a magnetic
signal, an electric signal, a radio signal, a microwave signal, or
a computer-readable storage medium.
[0134] By way of example, the software or computer program 116;126
may be realized as a computer program product, which is normally
carried or stored on a computer-readable medium 117;127, in
particular a non-volatile medium. The computer-readable medium may
include one or more removable or non-removable memory devices
including, but not limited to a Read-Only Memory (ROM), a Random
Access Memory (RAM), a Compact Disc (CD), a Digital Versatile Disc
(DVD), a Blu-ray disc, a Universal Serial Bus (USB) memory, a Hard
Disk Drive (HDD) storage device, a flash memory, a magnetic tape,
or any other conventional memory device. The computer program may
thus be loaded into the operating memory of a computer or
equivalent processing device for execution by the processing
circuitry thereof.
[0135] The flow diagram or diagrams presented herein may be
regarded as a computer flow diagram or diagrams, when performed by
one or more processors. A corresponding apparatus may be defined as
a group of function modules, where each step performed by the
processor corresponds to a function module. In this case, the
function modules are implemented as a computer program running on
the processor.
[0136] The computer program residing in memory may thus be
organized as appropriate function modules configured to perform,
when executed by the processor, at least part of the steps and/or
tasks described herein.
[0137] FIG. 15 is a schematic diagram illustrating an example of a
wireless communication device 20. The wireless communication device
20 comprises a receiver 510 for receiving a first downlink control
information on a first assignment from a radio network node. The
first downlink control information comprises a reference to a
second assignment from the radio network node on which a second
downlink control information is assigned to be received. The
wireless communication device 20 further comprises a determining
module 520 for determining if the second downlink control
information is obtainable by the wireless communication device. The
wireless communication device 20 further comprises a transmitter
530 for transmitting an indication indicating whether or not the
second downlink control information was obtainable to the radio
network node.
[0138] FIG. 16 is a schematic diagram illustrating an example of a
radio network node 10. The radio network node 10 comprises a
transmitter 560 for transmitting a first downlink control
information on a first assignment to a wireless communication
device. The first downlink control information comprises a
reference to a second assignment. The transmitter 560 is further
for transmitting a second downlink control information on the
second assignment to the wireless communication device. The radio
network node 10 further comprises a determination module 570 for
determining whether or not the second downlink control information
was obtainable by the wireless communication device. The
transmitter 560 is further for transmitting a third downlink
control information on a third assignment based on the determining
whether or not the second downlink control information was
obtainable in the wireless communication device.
[0139] Alternatively it is possible to realize the module(s)
predominantly by hardware modules, or alternatively by hardware,
with suitable interconnections between relevant modules. Particular
examples include one or more suitably configured digital signal
processors and other known electronic circuits, e.g. discrete logic
gates interconnected to perform a specialized function, and/or
Application Specific Integrated Circuits (ASICs) as previously
mentioned. Other examples of usable hardware include input/output
(I/O) circuitry and/or circuitry for receiving and/or sending
signals. The extent of software versus hardware is purely
implementation selection.
[0140] It is becoming increasingly popular to provide computing
services (hardware and/or software) network devices such as network
nodes and/or servers where the resources are delivered as a service
to remote locations over a network. By way of example, this means
that functionality, as described herein, can be distributed or
re-located to one or more separate physical nodes or servers. The
functionality may be re-located or distributed to one or more
jointly acting physical and/or virtual machines that can be
positioned in separate physical node(s), i.e. in the so-called
cloud. This is sometimes also referred to as cloud computing, which
is a model for enabling ubiquitous on-demand network access to a
pool of configurable computing resources such as networks, servers,
storage, applications and general or customized services.
[0141] There are different forms of virtualization that can be
useful in this context, including one or more of:
[0142] Consolidation of network functionality into virtualized
software running on customized or generic hardware. This is
sometimes referred to as network function virtualization.
[0143] Co-location of one or more application stacks, including
operating system, running on separate hardware onto a single
hardware platform. This is sometimes referred to as system
virtualization, or platform virtualization.
[0144] Co-location of hardware and/or software resources with the
objective of using some advanced domain level scheduling and
coordination technique to gain increased system resource
utilization. This is sometimes referred to as resource
virtualization, or centralized and coordinated resource
pooling.
[0145] Although it may often desirable to centralize functionality
in so-called generic data centers, in other scenarios it may in
fact be beneficial to distribute functionality over different parts
of the network.
[0146] In one particular embodiment of a method in a wireless
communication device for communication with a radio network node,
the method comprises the steps of: [0147] receiving a first
downlink control information on a first assignment from said radio
network node; [0148] said first downlink control information
comprises a reference to a second assignment from the radio network
node on which a second downlink control information is assigned to
be received; [0149] determining if the second downlink control
information is obtainable by the wireless communication device; and
[0150] transmitting an indication indicating whether or not the
second downlink control information was obtainable to the radio
network node.
[0151] In a further particular embodiment, the first assignment is
an assignment in a physical control channel.
[0152] In another further particular embodiment, the first
assignment is an assignment in a physical data channel.
[0153] In a further particular embodiment, the second assignment is
an assignment in a physical data channel.
[0154] In a further particular embodiment, the steps of determining
if the second downlink control information is obtainable by the
wireless communication device and transmitting an indication
indicating whether or not the second downlink control information
was obtainable to the radio network node are triggered by the
second assignment being an assignment in a physical data
channel.
[0155] In a further particular embodiment, the steps of determining
if the second downlink control information is obtainable by the
wireless communication device and transmitting an indication
indicating whether or not the second downlink control information
was obtainable to the radio network node are performed according to
standard specifications for particular transmission modes.
[0156] In another further particular embodiment, the steps of
determining if the second downlink control information is
obtainable by the wireless communication device and transmitting an
indication indicating whether or not the second downlink control
information was obtainable to the radio network node are requested
by a configuration message sent from the radio network node to the
wireless communication device.
[0157] In yet another further particular embodiment, the steps of
determining if the second downlink control information is
obtainable by the wireless communication device and transmitting an
indication indicating whether or not the second downlink control
information was obtainable to the radio network node are requested
by an indicator request in a downlink control information.
[0158] In a further particular embodiment, the indicator request
comprises a resource assignment for the transmitting of the
indication.
[0159] In a further particular embodiment, the indicator, if the
resource assignment for the transmitting of the indication is
assigned to a same assignment for an already granted uplink
assignment, is incorporated in an uplink message on the same
assignment for an already granted uplink assignment and the
particular assignment for the transmitting of the indication is
ignored.
[0160] In a further particular embodiment, the first downlink
control information is comprised in a medium access control
element.
[0161] In a further particular embodiment, the second downlink
control information is comprised in a medium access control
element.
[0162] In a further particular embodiment, the indication is
transmitted on a contention-based resource.
[0163] In another further particular embodiment, the indication is
incorporated into an already granted uplink assignment.
[0164] In a further particular embodiment, the transmitting of the
indication is performed using binary phase shift keying
signalling.
[0165] In another further particular embodiment, the transmitting
of the indication is performed only if the second downlink control
information was obtainable.
[0166] In yet another further particular embodiment, the
transmitting of the indication is performed only if the second
downlink control information was not obtainable.
[0167] In yet another further particular embodiment, the
transmitting of the indication performed using ON/OFF
signalling.
[0168] In a particular embodiment of a method in a radio network
node for communication with a wireless communication device, the
method comprises the steps of: [0169] transmitting a first downlink
control information on a first assignment to the wireless
communication device; [0170] the first downlink control information
comprises a reference to a second assignment; [0171] transmitting a
second downlink control information on the second assignment to the
wireless communication device; [0172] determining whether or not
the second downlink control information was obtainable by the
wireless communication device; and [0173] transmitting a third
downlink control information on a third assignment based on the
determining whether or not the second downlink control information
was obtainable in the wireless communication device.
[0174] In a further particular embodiment, the third downlink
control information comprises an initiation of a resending of
messages associated with the second downlink control
information.
[0175] In a further particular embodiment, the step of transmitting
a third downlink control information comprises transmitting, as a
response to a determination that the second downlink control
information was not obtainable by the wireless communication
device, the third downlink control information.
[0176] In a further particular embodiment, the step of determining
whether or not the second downlink control information was
obtainable by the wireless communication device comprises receiving
of an indication from the wireless communication device indicating
that the second downlink control information was not obtainable by
the wireless communication device.
[0177] In a further particular embodiment, the indication is
received on a contention-based resource.
[0178] In a further particular embodiment, the indication is
incorporated into an uplink assignment.
[0179] In another further particular embodiment, the receiving of
the indication is performed using binary phase shift keying
signalling.
[0180] In yet another further particular embodiment, the receiving
of the indication is performed using ON/OFF signalling.
[0181] In a further particular embodiment, the step of determining
whether or not the second downlink control information was
obtainable by the wireless communication device comprises
determining an absence of an indication from the wireless
communication device indicating that the second downlink control
information was obtainable by the wireless communication device
when such an indication was expected to be received.
[0182] In a further particular embodiment, the first assignment is
an assignment in a physical control channel.
[0183] In another further particular embodiment, the first
assignment is an assignment in a physical data channel.
[0184] In a further particular embodiment, the second assignment is
an assignment in a physical data channel.
[0185] A further particular embodiment comprises the further step
of transmitting, to the wireless communication device, a request
for transmitting an indication indicating whether or riot the
second downlink control information was obtainable by the wireless
communication device.
[0186] In a further particular embodiment, the request for
transmitting an indication is comprised in a configuration
message.
[0187] In another further particular embodiment, the request for
transmitting an indication is comprised in a downlink control
information.
[0188] In a further particular embodiment, the indicator request
comprises a resource assignment for the transmitting of the
indication.
[0189] In a further particular embodiment, the first downlink
control information is comprised in a medium access control
element.
[0190] In a further particular embodiment, the second downlink
control information is comprised in a medium access control
element.
[0191] A particular embodiment of a wireless communication device
is configured to: [0192] receive a first downlink control
information on a first assignment from a radio network node; [0193]
the first downlink control information comprises a reference to a
second assignment from the radio network node on which a second
downlink control information is assigned to be received; [0194]
determine if the second downlink control information is obtainable
by the wireless communication device; and [0195] transmit an
indication indicating whether or not the second downlink control
information was obtainable to the radio network node.
[0196] In a further particular embodiment, the wireless
communication device comprises a processor and a memory, the memory
comprising instructions executable by the processor, whereby the
processor is operative to determine if the second downlink control
information is obtainable by the wireless communication device.
[0197] In a further particular embodiment, the wireless
communication device comprises communication circuitry configured
to receive the first downlink control information on the first
assignment from the radio network node, and to transmit the
indication indicating whether or not the second downlink control
information was obtainable to the radio network node.
[0198] A particular embodiment of a radio network node is
configured to: [0199] transmit a first downlink control information
on a first assignment to a wireless communication device; [0200]
the first downlink control information comprises a reference to a
second assignment; [0201] transmit a second downlink control
information on the second assignment to the wireless communication
device; [0202] determine whether or not the second downlink control
information was obtainable by the wireless communication device;
and [0203] transmit a third downlink control information on a third
assignment based on the determining whether or not the second
downlink control information was obtainable in the wireless
communication device.
[0204] In a further particular embodiment, the radio network node
comprises a processor and a memory, the memory comprising
instructions executable by the processor, whereby the processor is
operative to determine whether or not the second downlink control
information was obtainable by the wireless communication
device.
[0205] In a further particular embodiment, the radio network node
comprises communication circuitry configured to transmit the first
assignment, to transmit the first downlink control information on
the first assignment to the wireless communication device, to
transmit the second downlink control information on the second
assignment to the wireless communication device, and to transmit
said third downlink control information on the third assignment to
the wireless communication device.
[0206] A particular embodiment of a computer program comprises
instructions, which when executed by at least one processor, cause
the at least one processor to receive a first downlink control
information on a first assignment from a radio network node, the
first downlink control information comprises a reference to a
second assignment from said radio network node on which a second
downlink control information is assigned to be received, to
determine if the second downlink control information is obtainable
by the wireless communication device, and to transmit an indication
indicating whether or not the second downlink control information
was obtainable by the wireless communication device.
[0207] A particular embodiment of a computer program comprises
instructions, which when executed by at least one processor, cause
the at least one processor to transmit a first downlink control
information on a first assignment to a wireless communication
device, the first downlink control information comprises a
reference to a second assignment, to transmit a second downlink
control information on the second assignment to the wireless
communication device, to determine whether or not the second
downlink control information was obtainable by the wireless
communication device, and to transmit a third downlink control
information on a third assignment based on the determining whether
or not the second downlink control information was obtainable in
the wireless communication device.
[0208] A particular embodiment of a computer-program product
comprising a computer-readable medium having stored thereon a
computer program according to the embodiment above.
[0209] A particular embodiment of a carrier comprising the computer
program of the embodiment above, wherein the carrier is one of an
electronic signal, an optical signal, an electromagnetic signal, a
magnetic signal, an electric signal, a radio signal, a microwave
signal, or a computer-readable storage medium.
[0210] A particular embodiment of a wireless communication device
comprises: [0211] a receiver for receiving a first downlink control
information on a first assignment from a radio network node; [0212]
the first downlink control information comprises a reference to a
second assignment from the radio network node on which a second
downlink control information is assigned to be received; [0213] a
determining module for determining if the second downlink control
information is obtainable by the wireless communication device; and
[0214] a transmitter for transmitting an indication indicating
whether or not the second downlink control information was
obtainable by the wireless communication device.
[0215] A particular embodiment of a radio network node comprises:
[0216] a transmitter for transmitting a first downlink control
information on a first assignment to a wireless communication
device; [0217] the first downlink control information comprises a
reference to a second assignment; [0218] the transmitter being
further for transmitting a second downlink control information on
the second assignment to the wireless communication device; [0219]
a determination module for determining whether or not the second
downlink control information was obtainable by the wireless
communication device; and [0220] the transmitter being further for
transmitting a third downlink control information on a third
assignment based on the determining whether or not the second
downlink control information was obtainable in the wireless
communication device.
[0221] The embodiments described above are merely given as
examples, and it should be understood that the proposed technology
is not limited thereto. It will be understood by those skilled in
the art that various modifications, combinations and changes may be
made to the embodiments without departing from the present scope as
defined by the appended claims. In particular, different part
solutions in the different embodiments can be combined in other
configurations, where technically possible.
ABBREVIATIONS
[0222] 3GPP Third Generation Partnership Project
[0223] ASIC Application Specific Integrated Circuits
[0224] BPSK Binary Phase Shift Keying
[0225] BTS Base Transceiver Stations
[0226] CD Compact Disc
[0227] COTS Common Off-The-Shelf
[0228] CPE Customer Premises Equipment
[0229] CPU Central Processing Units
[0230] CQI Channel-Quality Indicator
[0231] CRC Cyclic Redundancy Check
[0232] CRS Cell-Specific Reference Symbol
[0233] CSI Channel-State Information
[0234] CSI-IM CSI Interference Measurement
[0235] CSI-RS CSI Reference Symbol
[0236] DCI Downlink Control Information
[0237] DL DownLink
[0238] dPDCH direct Physical Data Channel
[0239] DSP Digital Signal Processors
[0240] DVD Digital Versatile Disc
[0241] eNB evolved Node B
[0242] ePDCCH enhanced Physical Downlink Control Channel
[0243] FDD Frequency Division Duplex
[0244] FPGA Field Programmable Gate Arrays
[0245] HARQ Hybrid Automatic Repeat-reQuest
[0246] HDD Hard Disk Drive
[0247] HW hardware
[0248] I/O input/output
[0249] LEE Laptop Embedded Equipment
[0250] LME Laptop Mounted Equipment
[0251] LTE Long Term Evolution
[0252] MAC Medium Access Control
[0253] MCS Modulation and Coding Scheme
[0254] MEM memory units
[0255] MI Mutual Information
[0256] MIMO Multiple Input Multiple Output
[0257] ND Network Device
[0258] NDI New Data Indicator
[0259] NI Network Interfaces
[0260] NIC Network Interface Controller
[0261] OFDM Orthogonal Frequency-Division Multiplexing
[0262] OS Operating System
[0263] OSS Operations and Support System
[0264] PC Personal Computer
[0265] PCCH Physical Control Channel
[0266] PDA Personal Digital Assistant
[0267] PDCCH Physical Downlink Control Channel
[0268] PDCH Physical Data Channel.
[0269] PDU Protocol Data Unit
[0270] PLC Programmable Logic Controllers
[0271] PMI Pre-coding Matrix Indicator
[0272] PRB Physical Resource Block
[0273] RAM Random Access Memory
[0274] REG registers
[0275] RI Rank Indicator
[0276] ROM Read-Only Memory
[0277] rPDCH re-transmittable Physical Data Channel
[0278] RRC Radio Resource Control
[0279] RRU Remote Radio Units
[0280] RV Redundancy Version
[0281] STA Station
[0282] SW software
[0283] TM Transmission Mode
[0284] TTI Transmission Time Interval
[0285] UE User Equipment
[0286] UL UpLink
[0287] USB Universal Serial Bus
[0288] WNIC Wireless Network interface Controller
* * * * *